The present disclosure relates to a vehicle driving device including a rotary electrical machine, and an inverter device for controlling the rotary electrical machine.
For example, a rotary electrical machine included in a driving device as a driving force source of a wheel or a kinetic energy regenerating device in a hybrid vehicle normally requires an inverter device configured with a switching element as a main body. The rotary electrical machine and the inverter device are electrically connected using a wiring member, and thus can be disposed at different positions from each other. However, the rotary electrical machine and the inverter device are desirably integrated in one case in view of the convenience in mounting on to the vehicle. From such standpoint, the vehicle driving device in which an inverter device [inverters 41, 42] for controlling a rotary electrical machine [generator 1, motor 2] is integrated with a case [driving device case 3] for accommodating the rotary electrical machine, and the like is disclosed in Japanese Patent Application Publication No. 2004-343845.
In the device of Japanese Patent Application Publication No. 2004-343845, the case includes a first case section [front case 31] for accommodating one rotary electrical machine [generator 1] and a second case section [rear case 32] for accommodating the other rotary electrical machine [motor 2] and a transmission device [under drive device U]. The first case section and the second case section are joined to each other in an axial direction (direction in which a rotation axis center of the rotary electrical machine extends). A cover member [inverter case 40 and cover 46] is attached to cross the first case section and the second case section, and the inverter device is accommodated in a space formed inside thereof.
However, the structure in which the cover member is provided across the first case section and the second case section as in Japanese Patent Application Publication No. 2004-343845 has a problem in that the physical size of the entire device tends to become large. Furthermore, a relatively complex seal structure is required to prevent liquid such as water, oil, and the like from entering an accommodation chamber of the inverter device. For example, in the structure shown in FIG. 5 of Japanese Patent Application Publication No. 2004-343845, a seal member [52 A, 52 B] for sealing between the cover member and the case sections is required for each of the first case section and the second case section. In the structure shown in FIG. 3 of Japanese Patent Application Publication No. 2004-343845, a common seal member [52] that is provided across the first case section and the second case section is used. In this case, a seal member that can absorb a step difference is required and a relatively great amount of seal member is also required on a mating surface between the two case sections.
In the device of Japanese Patent Application Publication No. 2004-343845, the wiring member extending from the inverter device is inserted into a through hole provided in the outer peripheral wall of the first case section and then connected to the rotary electrical machine in the first case section, and the wiring member is disposed in a space on the outer peripheral side of the first case section. Thus, a seal member provided across the first case section and the second case section is required to appropriately seal the entire wiring structure. A seal structure related to the cover member can be simplified by providing the cover member only on the second case section. However, two areas, between the wiring member and the cover member and between the wiring member and the first case section, are required as the sealing area of the wiring member, and hence a complex seal structure is required as a whole in the result.
As described in Japanese Patent Application Publication No. 2008-301572, a structure in which a wiring member introduced from an inverter device [PCU 300] to a case [divided accommodation case 13 and divided accommodation case 23] is connected to a rotary electrical machine [motor generator MG1] in the case is also known. However, Japanese Patent Application Publication No. 2008-301572 does not refer to the seal structure.